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Nathan Frank Bandstand by Richard Keeling on 500px.com

I developed eleven rolls of color film over the weekend.

Film dating back to October of last year, such as the shot above of the Nathan Frank Bandstand in Forest Park, St. Louis. It was pleasing to be reminded of warmer and more colorful times on a bleak winter’s weekend.

So why eleven?

Simply because I need to batch process film. If I don’t develop over a short period, the developing chemicals, primarily the C-41 developer and the blix (bleach-fix) components, begin to lose potency as they have a shelf life as mixed liquid of only a few days.

I used a developing kit made by Unicolor. This is, as far as I can tell, identical to the Jobo Press kit that is another popular home developing kit.

I always buy the 2 liter capacity kit. As the chemicals are shipped dry and not in solution, it’s relatively easy (assuming you have access to an accurate balance as I do) to split the packaged chemicals into three separate lots, each designed to be used with a 660 ml working solution. 660 ml is a perfect volume for use with a 2 x 35mm roll Paterson developing tank and this what I use. Alternatively, I can use the same volume to develop a single roll of 120 film.

I get the impression from reading bulletin board posts that color developing is approached with trepidation by many people. In truth, it’s just as easy as black and white developing but it does require one component that is not needed for b&w, namely a constant temperature water bath.

I’m fortunate to have picked up a thermostat-controlled bath large enough to hold bottles of prewash, developer and blix that was a throw-away, but it is possible to make your own bath out of a tub and fish tank heater that will work just as well.

The important point is to get the temperature of your initial reagents up to about 39° C and to keep it there. This temperature is on the warm side of luke warm.

It’s also important to warm about three liters of tap water to approximately the same temperature to use as a post-blix wash, although a few degrees above or below 39° C makes no difference. I do this simply by running a hot/cold stream from the faucet and judging the temp with my skin and confirming with my thermometer.  It’s surprising easy to get the temperature about right.

The wash is tap water. However, for preparing the powdered chemicals I use distilled water. Without any actual proof, I’m guessing that (based on my experience as a chemist) this preserves the developer and blix a bit better by not introducing any of the salts and ions found in ordinary tap water.

Once well warmed – I leave the bottles in the water bath at the correct temperature for an hour before use – the chemicals are ready to use. This is really very easy. Because the C-41 process is standardized in terms of developing times, all films, regardless of ISO, are treated in the same way. One minute of pre-wash with warmed water (I use distilled), 3.5 minutes in C-41 developer, 6.5 minutes in blix, a wash in water of 3 minutes and then addition of stabilizer solution for one minute, this latter step at room temperature. Although the kit does not require this step, I use a Kodak C-41 Final Rinse solution, essentially detergent plus preservatives, to complete the process. I then hang the film to dry thoroughly over several hours at room temperature before cutting and storing in archival sleeves.

That’s it. I can get up to 11 developed 36 frame 35mm rolls out of one 660 ml set of developing reagents as long as I do it all over the course of just a few days. I’ve not tried more than eleven but this number is about twice as much as the conservative recommendation offered in the kit directions. Next time I’ll stretch it to twelve. Developing this way saves a lot of money – it costs me about $1.20 per roll compared to $7.50 per roll offered by my local photo lab.

It’s also a lot of fun.